Structure of Ca-Mg-Zn Metallic Glasses (Preprint)

Abstract

The amorphous structure of four Ca60MgXZn40-X alloys (X = 10, 15, 20, and 25 at.%) has been modeled using a set of experimental neutron and X-ray scattering data, peak fit analysis, and Reverse Monte Carlo (RMC) simulation. The amorphous structure can be described as a mixture of Mg- and Zn- centered clusters, with Ca dominating in the first coordination shell of these clusters. The coordination number (CN) of 10 (with about 7 Ca and 3 (Mg+Zn) atoms) is the most common for the Zn-centered clusters. CN = 11 and 12 (with about 7-8 Ca and 4 (Mg+Zn) atoms) are the most common for the Mg-centered clusters. Fife-fold bond configurations (pentagonal pyramids) dominate (~60%) in the first coordination shell of the clusters, suggesting densely atomic packing. Bond angle distributions suggest the near-equilateral triangles and pentagonal pyramids to be the most common nearest atom configurations. Two Ca-Mg-Zn alloys with inferior GFA have increased amounts of (0,0,12,0), (0,2,8,1), (0,2,8,2) and (0,4,4,3) clusters, which suggests that these clusters may facilitate crystallization.

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 2011
Accession Number
ADA550867

Entities

People

  • A. C. Hannon
  • D. B. Miracle
  • E. B. Barney
  • E. Ma
  • O.N. Senkov
  • Yan Cheng

Organizations

  • Universal Energy Systems

Tags

DTIC Thesaurus Topics

  • Air Force
  • Air Force Facilities
  • Air Force Research Laboratories
  • Crystal Structure
  • Crystallization
  • Diffraction
  • Distribution Functions
  • Geometry
  • Materials
  • Military Research
  • Phase
  • Scattering
  • Simulations
  • Temperature Gradients
  • Triangles
  • X Ray Scattering
  • X Rays

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.
  • Quantum Chemistry